The present invention relates to an air-bag arrangement, and more particularly relates to an air-bag arrangement adapted to protect a driver or passenger in a motor vehicle such as a motor car.
It has been proposed to provide an air-bag in a motor car positioned in front of the driver or in front of a passenger of the motor car, the bag being adapted to inflate in the event that an accident arises. The bag thus provides a "cushion" for the driver or the passenger.
The design of air-bags is nor very sophisticated and the bag is adapted to be inflated before the driver or passenger moves forwardly within the motor vehicle during an accident as a result of vehicle retardation.
Reference may be made to EP-A-0344422 which discloses a bag in which parts of the bag are folded together to form a "tuck" by stitching, the stitching forming a "tear seam". The main purpose of this is to control the way that the bag is inflated. Thus the "tear seam" effectively controls the speed of inflation or the direction in which the bag expands during inflation so that the bag, when it is inflated, does not hit the driver or passenger with a significant force. The "tear seam" is designed to tear or rip, enabling the "tuck" to open out at a predetermined instant during the inflation of the bag thus effectively increasing the permissible interior volume of the bag at that instant.
One disadvantage of the system of EP-A-0344422 is that the "tear seam" comprises stitching which passes through part of the bag and which forms the boundary between the interior of the bag and the exterior of the bag. When the "tear seam" tears or rips, either the thread forming the stitching can break or the fabric in the region of the seam can tear. It is possible that the fabric will tear along the line of the stitching, since the fabric will have been pierced by the needle when the stitches have been put in place, and the fabric may thus have been punctured or weakened in the line of the stitching. However, it is also possible that the fabric adjacent the actual stitching may tear or rip. In any event, it is quit possible that the fabric of the bag may become damaged. If the fabric of the bag is damaged, and is apertured, the bag may deflate in an undesirable manner, and the bag will then not provide the desired cushioning effect.